This is your basic priority system. Pop Icy Veins, Time Warp, and trinkets as indicated by fight mecahnics and common sense. Alter Time as indicated below.

Your chosen level 90 talent is worth a lot of damage. If it can be triggered before the pull, do it. Keep it up as much as possible. It helps your elemental's damage as well.

Frozen Orb should be used on cooldown. It'll path roughly forward from you and slow down when it hits the first attackable target. The first impact will automatically grant you a fingers charge as well. It's also damned nice AOE, so try and aim it to maximize damage on as many targets as possible.

Your mage bomb of choice needs to be maintained, as it's your method to proc Brain Freeze. Both of the DoT style bombs can be refreshed during the time before their last tick without issue. Living Bomb will automatically explode and give you the full DPS while taking advantage of the DoT refresh mechanic. Nether Tempest is a bit harder, due to being a fraction of a second between ticks. Letting it fall off is a very minimal DPS loss, as is refreshing early.

Mirror Image is worth a decent amount of damage, but doesn't proc anything, so it's the last of the non-direct damage spells.

Frostfire Bolt with Brain Freeze up will let it benefit from Shatter. It only has one charge, so takes precedence.

Ice Lance with Fingers of Frost allows Ice Lance to benefit from Shatter and will launch your current Icicles set.

Frostbolt is your filler spell.

Frost uses Frost Armour. 7% haste beats out 3000 mastery and 5% crit.

Alter Time

This is a strange spell. When used, it takes a snapshot of your character's location, health, mana, buffs, and debuffs. You have 6 seconds to do anything short of dying, then it restores you to the snapshot's state. Use this in conjunction with Time Warp, Icy Veins, trinkets, even Incanter's Ward's damage buff. Anything you can squeeze more damage with. Be careful though, if you pop something during Alter Time, you'll lose it when it ends. You want to dump all your Fingers of Frost charges and Brain Freezes that you get ASAP.

Optimal use would be 2 charges of Fingers of Frost, a Brain Freeze proc, a full set of Icicles, Icy Veins, and whatever other DPS buffs you've got such as trinkets and potions. If you can't line it up with anything, use it on at least one Fingers of Frost, a Brain Freeze, and some Icicles. The extra damage you'll get out of those will almost always beat out an extra 6 seconds on something else. It's not hard to line it up though, do try to get some buffs in there as well.

Talents and Glyphs

Talents and glyphs both are now situational and likely to be changed on a per-fight basis for the most hardcore. We don't have to carry portal runes around anymore, so stock up on the reagent to do so. Learn the encounters and change your choices as you see fit. I won't go into which is used on what fight for what reasons.

Level 15: Presence of Mind is a single target, stationary, DPS boost. Fair warning, consider your haste values. If you're below GCD cap on Frostbolt, this isn't a DPS gain. If you're moving, then it's probably not the talent of choice. Ice Floes gives you three Frostbolts while moving, and if you cast it in the last 0.5 seconds of a Frostbolt cast, it won't consume a charge. Ice Floes is fairly amazing with the 5.4 changes, give it a fair try. Blazing Speed can potentially get you where you need to go, if Blink is on CD.

Level 30: Temporal Shield will heal off any non-fatal damage, or fatal with Cauterize. It's off the GCD. It's meant for large hits every few dozen seconds, not sustained damage. It will also reduce any damage taken by 15% while active. Ice Barrier holds more damage, but costs the GCD. It's better for large single hits often enough that you can't rely on Cauterize or Greater Invisibility, but you need the extra HP to survive it. Flameglow is our only real passive damage reduction skill, and really shines on many small hits, although it has been nerfed almost to the point of the other two being better in just about any current situation.

Level 45: Add control on Ring of Frost, an extra targetted nova on Ice Ward, or a silence tied to a freeze on Frostjaw. Frostjaw's silence is actually tied to the freeze debuff; it's honestly best used as an interrupt since it breaks on damage. Ice Warding the tank is a good option for timing Shatters with Frost Bomb. Your call.

Level 60: Cauterize is capped at preventing 200% of your total health. It takes 300% of your health to kill you in one hit. You can't solo soak some things that aren't meant to be, passively. You can still do it with Greater Invisibility, but that costs a GCD with the trade that it's only 90 seconds instead of 120 seconds cooldown. Consider Cold Snap for scenarios or something where you'll need self healing more than eating raid wipe mechanics. Cold Snap essentially allows you 2 Ice Blocks in close succession, then a 3 minute cooldown Ice Block instead of 5.

Level 75: Changes depending on encounter needs.

Living Bomb should be our single target bomb of choice. Comparing NT to LB at no haste, NT is 292.32% spell power. LB is 321.44% spell power on the DoT portion, where the explosion is always 10% more, so 32.14% at no haste.

Nether Tempest is our cleave bomb, doing 50% of its damage to a nearby target, as opposed to 10% as Living Bomb does.

Frost Bomb is our AOE bomb, doing 344.68% spell power every 10 seconds (reduced by haste), and half damage to secondary targets. It's only slightly behind Living Bomb for single target damage, so you're not out of luck for a single target burn if you need to AOE for part of the fight. Keep in mind: this is not a DoT, and will not trigger DoT based trinkets.

With regards to Brain Freeze, Nether Tempest is 9% per tick, Living Bomb is 25% per tick but not on the explosion, and Frost Bomb is 100%. Please remember the rules of probability when you're taking these. You can, and will, get screwed on procs. You will also have amazing streaks of luck.

Level 90: Also encounter dependant. Invocation is probably the general winner for raiding though. Haste is our best stat, and it only makes Invocation better. If you're able to stand and burn for the entire minute, Rune of Power will become slightly better DPS than Invocation. Incanter's Ward isn't generally a good idea for any fight, unless you're being lazy and just want the 6% damage passive.

Glyphs are fairly self explanitory. Read them. Take what's appropriate for the situation. Here's a few odd mechanics you should be aware of on some glyphs.

Glyph of Water Elemenetal has some buggy interactions with multiple targets. There's a chance it'll change targets on you, and not obey an attack command to change to yours, regardless of if on assist or defensive. Blizz knows and is working on a fix, but it's not really high priority. If you don't need your elemental by your side and it's a multi target fight, consider not using it and controlling it via Defensive Stance and Move To command.

Glyph of Icy Veins exists so we don't GCD cap our instant spells while under it. It's functionally the same, you're trading 20% faster damage for 20% more damage. The difference is, you don't gain faster bomb speeds. To make up for this, it has a hidden +20% modifier on Fingers of Frost proc chance while active. Take this glyph when you're over 50% haste, raid buffed, with icy veins up. Remember: don't stack IV with Time Warp while unglyphed, but do stack it when glyphed.

To that end, Nathyiel has compiled a list of various points where this point is hit in a raid with 5% haste:

Originally Posted by Nathyiel

The IV cap are:

25.00% haste full raid buff.

19.05% haste with only Frozen Armor.

11.25% haste from gear (4786 haste rating)

10.16% haste for Goblin (4318 haste rating)

I would like it noted that you do not stop stacking haste past this point. You continue to do so. It's just a break point where the added haste from IV is worth less than the 20% damage of glyphed IV.

Glyph of Evocation will proc on heal effects, but not while using Rune of Power.

Hit cap is 15%. Expertise now grants spell hit, so if you need extra reforges, or a red gem with hit, remember this. Racial bonuses for expertise do exist, make sure to account for this. It's a free 1% hit if you're using a matching weapon.

Haste is our best non-hit secondary stat. You cast faster, your DoTs tick faster, you gain procs faster. There is actually enough haste on gear these days that you can actually hard-cap Frostbolt's cast time. Haste is equal in value to Mastery from 14242 to 15697. Don't worry if you're above 14242 by a bit, it's still optimal. There is a Nether Tempest breakpoint at 15832, should you care to lose a tiny bit single target for the handful of Nether Tempest fights in the tier. It's minimal either way.

Mastery is interesting. Our mastery stores a percentage of any Frostbolt or Frostfire Bolt damage event as an Icicle above your head. You can have up to five at any given time, the oldest one will automatically launch when you gain a sixth. They will all fire in a rapid barrage when you cast Ice Lance. For any normal circumstances, you will not need to pay attention to them. They're passive damage, much like fire's Ignite. They can be used to finish off low health enemies, if you have a decent judgement of how much damage is stored in them, though the only point I've seen this specific trick useful has been Proving Grounds. In general, they can be saved up, along with procs, to help burn down a high priority target quickly.

Crit soft cap is 28% raid buffed. This includes the 5% crit buff from Arcane Brilliance. Shatter is crit percent*2+50%. The math behind this is (((28-3)*2)+50)=100. You lose 1% crit against any target for every level higher than you are, before Shatter. Crit capping is not an important thing anymore.

Miscellaneous

SimulationCraft
Please learn how to simulate your character. It will allow you to not need to ask opinions on every little upgrade you get, and allows you to find out your own personal stat weights. A good video tutorial on how to do this is found here. A text tutorial from ages past here. I don't know why it was knocked off of sticky, honestly. It's still relevant.

Gems
The current meta gem to use is Burning Primal Diamond. This is +216 int and +3% damage when you crit. There is no argument and no contest for any other meta gem against this, outside of the legendary meta gem from 5.2.

Water Elemental Sound
Should you get sick of the Water Elemental bubbling sound, as I have, simply go into your WoW's Data folder, create a folder called Sound. Inside that, create a folder called Creature, then another inside that called WaterElemental. Now create a blank .wav in that folder and call it WaterElementalLoop.ogg, capitalization is important on these folders and the file. Make sure you change the .wav to .ogg.

If you guys see any issues or have any questions, feel free to post. I did write most of this at 3 AM or later, even though it was mostly an edit in place of the old one.

cool guide , im loving playing frost, but you didnt mention rune of power here? i actually prefer it to the silly invocation , because it lasts a whole minute and with pom its instant(invocation makes me feel stuck kind of), also do you think a macro could be posted that selects the focus target(eg selecting tank or mellee in most fights as the focus) casts ice-ward then return to current target? im kinda clueless with macros

cool guide , im loving playing frost, but you didnt mention rune of power here? i actually prefer it to the silly invocation , because it lasts a whole minute and with pom its instant(invocation makes me feel stuck kind of)

The problem with rune of power as frost against invoc, is that we stack haste. Invoc's 0% damage portion of the cycle will get 4 times smaller than rune's will, and invoc is better for any boss with a burst phase. Rune is fine and well, but optimal is simming to be invoc at higher gear levels.

, also do you think a macro could be posted that selects the focus target(eg selecting tank or mellee in most fights as the focus) casts ice-ward then return to current target? im kinda clueless with macros

Today we logged a world boss kill, Galleon (essentially a Patchwerk fight) and browsing the log after the kill I realized that WoL is currently bugged and not showing our Water Elemental damage. It's showing Water Elemental as a neutral creature.

The Water Ele ended up doing about 9%-18% of my damage (we had 2 frost mages in the raid, and I wasn't sure if I was correctly separating out my Water Ele damage)

Anyways, I believe frost is going to be the spec to go for a decent number of fights this tier. It'd be nice if the post-raid forums tomorrow isn't filled with QQ, "OMG Frost is so weak!" based on people not realizing the bug in WoL.

Sorry I just need clarification on one thing. If I can't reforge my crit high enough to reach cap, is mastery better than crit? (Haste is still my #1, this is just for after I've already reforged max haste).

Your question is actually already answered in the post if you read it more clearly, though I assume your problem is just an inadequate understanding of the notation.

Your stat priority is;
Intellect > hit/expertise > haste > crit to 28% > mastery > more crit
This means that first you want intellect, then haste, then crit if you are below the cap, then mastery, then crit if you are above the cap.
Crit is not useless unless you can hit the cap exactly, it is great until the cap and then less good afterwards.

Your question is actually already answered in the post if you read it more clearly, though I assume your problem is just an inadequate understanding of the notation.

Your stat priority is;
Intellect > hit/expertise > haste > crit to 28% > mastery > more crit
This means that first you want intellect, then haste, then crit if you are below the cap, then mastery, then crit if you are above the cap.
Crit is not useless unless you can hit the cap exactly, it is great until the cap and then less good afterwards.

Thats what I assumed. I just wanted to make sure it wasn't a 'crit to 28% (if you can reach it)' kind of thing. Okay great thanks for the help!

Yeah, this isn't like fire where you gear for X amount of haste because you get an extra tick. This is purely because speed = more procs. You can't ever have enough, until you hard cap frostbolt to 1 second cast, at 100% haste.